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From: "emmanuel.le-trong@cnrs-orleans.fr" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/98216] New: [C++20] std::array<double, N> template parameter error with negative values Date: Wed, 09 Dec 2020 15:43:15 +0000 [thread overview] Message-ID: <bug-98216-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98216 Bug ID: 98216 Summary: [C++20] std::array<double, N> template parameter error with negative values Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: emmanuel.le-trong@cnrs-orleans.fr Target Milestone: --- Sorry for the bad title, I can't figure out how to summarize this: #include <array> #include <cassert> using an_array = std::array <double, 1>; constexpr auto add_array (an_array a, an_array const& b) { a[0] += b[0]; return a; } template <an_array A> struct wrapper { static constexpr auto arr = A; }; template <an_array A1 ,an_array A2 > auto add (wrapper <A1> const&, wrapper <A2> const&) { return wrapper <add_array (A1, A2)> {}; } constexpr auto ONE = an_array {{ 1. }}; constexpr auto MINUS_ONE = an_array {{ -1. }}; constexpr auto MINUS_TWO = an_array {{ -2. }}; int main () { auto a = wrapper <MINUS_TWO> {}; auto b = wrapper <ONE> {}; auto c = add (a, b); assert (c.arr == MINUS_TWO); // <- should fail assert (c.arr == MINUS_ONE); // <- should pass } Compiled with version 11.0.0 20201209, the first assertion passes and the second fails. It should be the opposite. FWIW, if you replace double by float, it works as intended.
next reply other threads:[~2020-12-09 15:43 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-12-09 15:43 emmanuel.le-trong@cnrs-orleans.fr [this message] 2020-12-09 16:04 ` [Bug c++/98216] " redi at gcc dot gnu.org 2020-12-10 7:33 ` rguenth at gcc dot gnu.org 2020-12-10 17:05 ` redi at gcc dot gnu.org 2020-12-10 17:16 ` redi at gcc dot gnu.org 2020-12-10 17:56 ` emmanuel.le-trong@cnrs-orleans.fr 2020-12-14 20:56 ` ppalka at gcc dot gnu.org 2021-07-27 8:08 ` [Bug c++/98216] [C++20] template mangling for double template argument is wrong pinskia at gcc dot gnu.org 2021-09-23 18:57 ` ppalka at gcc dot gnu.org 2021-09-23 19:01 ` ppalka at gcc dot gnu.org 2021-09-24 16:36 ` cvs-commit at gcc dot gnu.org 2021-09-24 19:36 ` emmanuel.le-trong@cnrs-orleans.fr 2021-10-06 14:15 ` cvs-commit at gcc dot gnu.org 2021-10-14 19:06 ` hq.ks at web dot de 2021-10-14 21:39 ` pinskia at gcc dot gnu.org
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